Ship-propeller.



L. vWMUBLANG e N. LALLIE.

SHIP PROPBLLER.

APPLIOATION FILED JULYS, 1912.

Patented Sept. 30, 1913.

i 25%* 5% and y 5W .weee e@ LON MAUBLANC AND NORBERT LALLI, OF NANTES,FRANCE.

SHIP-PROPELLER.

Specification of Letters Patent.

Patented Sept. 30, 1913.

Application led July 9, 1912. Serial No. 708,486.

To all whom t may concern:

Be it known that we, LEON MAUBLANC and NORBERT LALLI, citizens of theFrench Republic, and residents of Nantes, France, have invented certainnew and useful lmprovements in Ship.Propellers,'of which the followingis a specification.

The present invention relates to a ,propeller screw the object of whichis to so arrange the blades that they may be spaced from the shaft fromthe front portion of the propeller to a supporting hub, whereby theblades will operate in still water.

Owing to the construction` of 'the propeller, the entire surface of theblades are efficiently utilized to avoid centrifugal e'ect in the massof the expelled water, and loss of motive power. rlhe propeller bladesare so shaped that, while rotating, they generate a cylinder and repelthe whole corresponde ing cylindrical mass of water exclusively to,-ward the rear at a uniform speed inthe direction of the axis of thepropeller'shaft, s0 that each drop Of water entering at one end Of thepropeller slides all along the surface of a blade. Y

The View accompanying drawing illustrates a side elevation of theimproved propeller. Y

At the rear end of the propeller shaftl is secured a hub 2. From twodiametrically opposed portions of said hub two blades 3 and 4symmetrically extend radially and normally with respect to said shaftand thence forward inthe direction of the motion (arrow 5) to the extentof half a pitch without contacting with the shaft l. The inner edges ofthe blades 3 and 4, are spaced from the shaft l, to provide a passage `6for the water said blades beginning at their inner edge with a slope of30 degrees.

The rear inner portions '7 and 8 of the propeller' blades 3 and l are asnarrow as possible and the adapted slope is such that it correspondstothe real speed of the repelled water, that is to say, to the speedtransmitted to thc water by the efficient portion ofthe blade, less therecoil.

From the foregoing it results that the improved propeller is U shaped,the legs of the U being helically bent around the longitudipeciallytheir efficient working portions are Operating in still water which isbeyond the hub, that is to say the water which has not been agitated orwhirled either by a hub or by fastening arms.

Owing to the fact that the blades are secured attheir rear ends,resistance Of the ywater when the propeller is voperating is greatlyreduced. y

Having now fully described our Said invention, what we claim and desireto secure by Letters Patent, is:

l. A propeller comprising a shaft, a hub at the rear end of said shaft,two blades secured at two diametrically Opposite points on said hub,said blades opposite the hub extending radially from said shaft, theblades extending forwardly in helical form around said shaft and spacedtherefrom to form a passage between said blades and the shaft from thefront portion of the propeller to the hub. Y

2. A propeller comprising a shaft, a hub at the rear end of the shaft,and blades secured to opposite sides of the hub and extending forwardlytherefrom in helical forni around the shaft, the inner edges of theblades from the hub being spaced from the shaft to form a passage fromthe front portion of the propeller to the hub, the front edge of theblades being sharpened to form cutters.

In testimony whereof we have hereunto set our hands in presence Of twowitnesses.

LON MAUBLANC. NORBERT LALLIE.

Witnesses: f

LOUIS GOLDSGHMIDT, RAOUL EHOMZEAU.

Copies of this patent may be obtained VVfor ve cents each, by addressingthe Commissioner of Patents.

` Washington, D. C.

